Process of preparing tertiary acrylic acid esters from acetylene



Patented Sept. 29, 1953 PROCESS OF PREPARING TERTIARY" ACRYLIC ACIDESTERS' FROM ACETYLEN E Otto Albrecht,

Muenchenstein,

and. Arthur Maeder, Basel, Switzerland, assignors to Ciba Limited,Basel, Switzerland, a, Swiss firm N Drawing.

Application June-19, 1950, Serial No. 169,072. In Switzerland February21, 1947 7 Claims. 1

This application is a division of application Ser. No. 7998, filedFebruary 12, 1948, now abandoned.

According to this invention esters of olefine carboxylic acids are madeby treating a compound of the acetylene series with nickel carbonyl orcobalt carbonyl with the addition of an acid and of a hydroxy compoundwhich contains at least one hydroxy group bound to an aliphatic carbonatom, the three remaining valences of which are bound to carbon. In thismanner there are obtained from compounds containing the grouping CEC-,esters containing th grouping in which. -OR represents the residue ofthe hydroxy compound used having the formula HOR, or mixtures of such,an ester with the free olefine carboxylic acid. With acetylene there areobtained by this process esters of acrylic acid ormixtures of acrylicacid esters and free acrylic.

acid.

As a compound of the acetylene series acetylene itself is the preferred.starting material. However, there may also be used as starting materialssubstituted acetylenes such as methyl-acetylene, ethyl-acetylene,phenyl-acetylene, vinyl-acetylene, divinyl-acetylene,isopropenyl-acetylene, lethinyl-cyclohexene-(l) and also alkinols oralkine-dicls such as butine-(ll-ol-( l), pentene- (3)-ine-(1)-ol-(5),and, also ethers or esters thereof or products obtainable therefrom bydehydration; furthermore ketones of the acetylene series, such ashexene-(3)-ine-(5)-one-(2); also propiolic acid esters or otheracetylene carboxylic acid. esters, such as stearolic acid esters,dehydro-undecylenic acid esters, undecolic acid esters, behenolic acidesters. There are also to be mentioned among acetylene compounds whichmay be used as starting materials alkinols derived from steroid ketones,such as testosterone, or from tetralones, by the addition of acetylene.

As hydroxy compounds which contain at least one hydroxy group bound toan aliphatic carbon atom, the three remaining valences of which arebound to carbon, to be used as starting materials in the invention theremay be designated tertiary aliphatic. alcohols containing at least onehydroxy group, such as tertiary butyl alcohol and carbonyl compoundswhich are capable of reacting in the enol form, such as acetoacetic acidesters, a-IIlOIlO-SllbStltlltBd acetoacetic acid 2 esters;acetyl-acetone, oxalacetone or oxalacetic acid esters.

There may beused as acids in the present invention, for example,hydrohalicacids, especially hydrochloric acid, but also phosphoric acidor acetic acid. They are advantageously used in aqueous solution.

The reaction of the invention may be carried out by mixing the reactantstogether at room temperature or at a raised temperature, if de-- sired,in a pressure vessel. When acetylene and nickel carbonyl are used asstarting materials the reaction may be carried out at room temperatureor a moderately raised temperature, for example, at 30 C. underatmospheric pressure or under superatmospheric pressure. For example,acetylene may be introduced into a mixture of the hydroxy compound andthe acid and the nickel carbonyl introduced dropwise at the same time.It is still more advantageous to mix the hydroxy compound, acid andnickel car bonyl together, if desired, with the addition of a solvent,preferably aninert one, and to agitate themixture with. acetyleneiinasuitable agitating apparatus under slightly superatmospheric pressure.Substituted acetylenes of lower re activity, for example, alkinols, areadvantageously reacted with the metal carbonyl, especially nickelcarbonyl, at a raised temperature, for example, at 50-120 C., the use ofthe easily volatile nickel carbonyl making it necessary to work in apressure vessel.

For the purpose of working under atmospheric pressure there are used for1 mol of the acetylene compound at least 4 mol of nickel carbonyl orcobalt carbonyl, at least mol of a monobasic acid and at least 1 mol ofthe hydroxy compound. When the reaction is conducted in a pressurevessel at a raised temperature, for example, at -150 C., the quantity ofthe metal carbonyl may be reduced, but carbon monoxide must be presentin excess. It is also possible to form the metal carbonyl during thereaction, when the latter is conductedv at a raised temperature andunder pressure, by working in the presence of metallic nickel or cobaltor a salt thereof, especially a halide, with the addition of an excessof carbon monoxide. In this case only small quantities of nickel orcobalt or a salt thereof are necessary, as these additions act ascatalysts.

The process may be conducted discontinuously or continuously.

As already stated the products of the invention consist predominantly ofesters of carboxylic acids which contain a double bond in the 11:5-position, if desired, in admixture with the carboxylic acids from whichthe esters are derived. When necessary, the free olefine carboxylicacids present in the reaction mixture may be subsequently esterified.This may be brought about in the usual manner, for example, bydistilling off the water present in the reaction mixture, and heatingthe mixture containing the olefine carboxylic acid and the alcohol untilthe esterification ceases. The water may be removed during theesterification azeotropically or, in the case of high boiling alcohols,by evacuation.

Owing to the reactive double bond the products of the invention aresuitable, for example, as intermediate products, for instance, for themanufacture of polymerisates. The acrylic acid esters obtainable, forexample, from acetyleneg polymerise with the application of heat,especially in the presence of a polymerisation accelerator, such asbenzoyl peroxide, whereby polymerisates are obtained whose propertiesdepend on the choice of the starting materials.

Such polymeric acrylic acid esters can be used for producing coatings ontextiles or paper, and also as artificial substances or adhesives or asconstituents of lacquers, artificial masses or the like.

The following examples illustrate the invention, the parts being byweight unless otherwise stated, and the relationship of parts by weightto parts by volume being the same as that of the kilogram to the liter:

Example 1 (a) A solution of 34.7 parts of tertiary butanol (1 mol) in 90parts of benzene heated at 60 C. is agitated with acetylene under aslightly superatmospheric pressure after being mixed with 36 parts ofhydrochloric acid (density:l.l99) and parts of nickel carbonyl (1 mol)until gas is no longer absorbed. The reaction product is then filteredand the filtrate is fractionated by means of a column under atmosphericpressure. The ester of the formula distils at l-126 C. in the form of acolorless rather volatile liquid having a pungent tearproducing odor. Byheating it with a small quantity of benzoyl peroxide (for example 1 percent.) at 100 C. it is converted into a hard, colorless, translucentpolymerisate in a short time.

(b) parts of nickel carbonyl are introduced dropwise in the course ofone hour into a solution of 100 parts of tertiary butanol, 29.3 parts ofglacial acetic acid and 0.5 part of hydroquinone at a temperature of -45C. and under an absolute pressure of 1 /5 atmospheres of acetylene whilestirring.

After a further hour and when about 20 parts by volume of acetylene havebeen absorbed the reaction is finished.

The reaction mixture is mixed with a further 0.5 part of hydroquinoneand subjected to distillation with steam. The upper ester layer isseparated from the distillate, agitated in succession once with a normalsolution of sodium bicarbonate and then four times with 100 parts ofWater on each occasion, whereby acid constituents and the excess oftertiary butanol are removed. After drying with sodium sulfate in coolsurroundings there are obtained 51.5 parts of crude ester in the form ofa clear slightly yellow liquid. By fractional distillation under reducedpressure there are obtained therefrom 40 parts of the pure water-cleartertiary butyl-acrylate, boiling at 5l52.5 C. under 64-70 mm. pressure.

(0) 30 parts of nickel carbonyl are introduced dropwise into a mixtureof 100 parts of tertiary butanol, 30 parts of phosphoric acid of '70 percent. strength and 0.5 part of hydroquinone in a manner analogous tothat described under (a) above. In this case the nickel carbonyl isintroduced in the course of 1 hours. After a total of 6 hours thereaction is finished and by this time about 19 parts by volume ofacetylene will have been absorbed.

After the addition of a further 0.5 part of hydroquinone, the crudeester is removed from the reaction mixture by distillation with steam,the water is separated and the ester agitated 3 times with 50 parts of a1 N-solution of sodium bicarbonate and twice with 100 parts of water oneach ocasion. After drying with sodium sulfate in cool surroundings,there are obtained 40 parts of crude ester in the form of an almostcolorless liquid.

The crude product is fractionally distilled under reduced pressure toyield 30.5 parts of pure tertiary butyl aorylate. Instead of tertiarybutanol another tertiary alcohol, for instance, tertiary lauryl alcoholor a-tGlPlIlGOl may be used.

Ezrample 2 A solution, heated at 50 50 C. of 305 parts of acetoaceticacid ethyl ester (1 mol) and parts of benzene is agitated with acetyleneunder a slightly superatmospheric pressure, after the ad.- dition of 18parts of concentrated hydrochloric acid (density=l.l99) and 10 parts ofnickel carbonyl, until the gas is no longer absorbed. The reactionproceeds somewhat more slowly than in the case of primary alcohols. Thereaction product is filtered and the solvent is removed by distillation.The oily residue can be purified by distillation under reduced pressure.

By heating the crude ester with a small quantity of benzoyl peroxide(for example about 2 per cent.) on the water bath there is obtainedafter 2-3 hours a viscous resinous polymerisate.

Having thus described the invention, what is claimed is:

1. A process for the manufacture of an acrylic acid ester whichcomprises treating acetylene with nickel carbonyl with the addition ofan acid and of a hydroxy compound which. contains at one hydroxy groupbound to an aliphatic carbon atom, the three remaining valences of whichare bound to carbon.

2. A process for the manufacture of an acrylic acid ester whichcomprises treating acetylene with nickel carbonyl with the addition ofan acid and of a tertiary aliphatic alcohol.

3. A process for the manufacture of an acrylic acid ester whichcomprises treating acetylene with nickel carbonyl with the addition ofan acid and of tertiary butyl alcohol.

4. A process for the manufacture of an acrylic acid ester whichcomprises treating acetylene with nickel carbonyl with the addition ofanhydrous acetic acid and tertiary butyl alcohol at a temperature of40-50 C. and under an acetylene pressure which exceeds one atmosphere.

5. A process for the manufacture of an acrylic acid ester whichcomprises treating acetylene with nickel carbonyl with the addition ofan acid and of a hydroxy compound which contains at least one enolic.hydroxy group.

6. A process for the manufacture of an acrylic acid ester whichcomprises treating acetylene with nickel carbonyl with the addition ofan acid and of acetoacetic acid ethyl ester.

7. The ester of acrylic acid with acetoacetic acid ethyl ester.

OTTO ALBRECHT. ARTHUR MAEDER.

6 References Cited in the meet this patent UNITED STATES PATENTS NumberName Date 2,117,349 Neher May 1'7, 1938 2,466,738 Phillips Apr. 12, 1949OTHER REFERENCES Modern Plastics, v01. 23, pp. 162, 163 and 210 (Nov.1945).

Reppe, Advances in Acetylene Chemistry, (Intelligence Division ReportNo. 4149. Published by OTS as PB-1112, Jan. 25, 1946), pp. 21-23.

1. A PROCESS FOR THE MANUFACTURE OF AN ACRYLIC ACID ESTER WHICHCOMPRISES TREATING ACETYLENE WITH NICKEL CARBONYL WITH THE ADDITION OFAN ACID AND OF A HYDROXY COMPOUND WHICH CONTAINS AT LEAST ONE HYDROXYGROUP BOUND TO A ALIPHATIC CARBON ATOM, THE THREE REMAINING VALENCES OFWHICH ARE BOUND TO CARBON.